Apparatus for making colored sheet glass



March 4, 1941-. J. H. FOX

APPARATUS FOR MAKING COLORED SHEET GLASS:

Filed Jan. 6, 1938 4 Sheets-Sheet l /l/ll/I/I l/I INVENTUR. daH/v H. F X

vfia- RNEYS.

March 4, 1941. J. H. Fox 2,233,597 a I APPARATUS FOR llAKINflr COLORED SX-XEET GLASS Filed Jan. 6, 1938 4 Sheets-Sheet 2 March 4, 1941. ox

APPARATUS FOR MAKING COLORED SHEET GLASS 4 Sheets-Shet 5 Filed Jan. 6, 1938 mfa RNEYS.

' nvvmmn JOHN H. Fb/

March 4, 1941. J. FOX 2,233,597

APPARATUS FOR MAKING COLORED SHEET eLAss k Filed Jan. e, 1938 4 Sheets-Shet 4 RNEYS.

Patented Mar. 4, 1941 PATENT OFFICE APPARATUS FOR MAKING COLORED SHEET GLASS .l'ohnh. Fox, llttsburgh, Pa., assignor to Pittsburgh Plate Glass Company, Allegheny Gounty, Pa. a corporation of Pennsylvania Application January 6, 1938, No. 183,650

3Clalms.

. The invention relates to an apparatus whereby a colored glass may be made in an ordinary sheet glass machine, such as that of Slinglufl or Col- I burn, by simple additions thereto permitting the 5 making of ordinary colorless sheet glass when the color supply means are discontinued. It has been proposed heretofore to accomplish this result by feeding either colored glass in molten or powdered form onto the surface oi the bath adjacent the line or draw of the sheet, so that a colored layer is supplied to one side of the sheet, the body of the sheet being or clear glass. This two-layer glass, known as flashed glass, has a coating which is relatively thin and transparent, tending in some cases to separate from the body or clear glass, ii the two glasses are not exactly fitted to each other". The present invention has for its objects the provision oi an improved apparatus which will give a sheet colored throughout its central portion, as opposed to the "flashed" or two-layer glass, and which shows, with transmitted light, denser color and less-transparency.

'hvoiorms of the apparatus are shown in the accompanying drawings, wherein:

Figure l is a partial vertical section through the apparatus. Fig; 2 is a detail perspective view. Fig. '3 is a vertical section through a moditication on-the line III-III of Fig. 5. Fig. 4 is a 3o horizontal section on the line IV-,IV of Fig. 3.

Fig. 5 is a section on the line V-V of Fig. 3. Fig.

Baisasectionalviewshowingthemeansiorclosingtheslotthroughthedrawbarlnthem.3

construction. AndFigJissdetall section showingarurthermodiilcation.

Referring to the construction shown inl'lgs. 1 and2,'|istheendotameltingtaukandlisa iorehearth or drawing kiln, over which is mounted adrawing machine comprising the caslnglandthe'pairsoi driven rolls II. by means of which a sheet Ills drawn continuously from thebathintheiorehearth. 'Ihisisawellknown drawhzgmachineorthel'ourcaultorslinglufl type. and in operation, the glass sheet emerging gsimmthetopofthecssinglscutlnsectionsand removedintheusuaimanner. Th'eiorehearthis provldedwiththeusualskimbarll andis ooveredbytheplatesilandiiandtheusual L-blocksii. ktendingtrsnsverselyottheiorelohearthisadrawbariioiretractorymaterial chamber ll of approximately circular cross section extending throughout the length of the forehearth and registering at its ends in a pair of containers ll, i! (Fig. 2) which are formed in the side walls of the tank. The upper side of the 5 chamber i1 is provided with an outlet slot I! for the passage of the glass which is led to the cham ber ll from the containers I; ii.

In operating the machine, molten colored glass is supplied to the containers II at intervals by 19 means of ladies which remove the colored glass from a supplemental melting tank. The molten colored glass, thus supplied to the containers, flows through the chamber i1, filling it and is fed upward through the slot l, the rate of flow being controlled by the head pressurein the containers II, it. The sheet H, which is drawn irom the bath, consists to a substantial extent 01' clear glass, which is supplied from the bath in the torehearth, such clear glass forming 'the'surface layers of the sheet. The colored glass'supplied from the chamber ll flows upward through the bath and forms the central layer of thesheet.

As there is a tendency of the glass, to treeze in the chamber II, this action is guarded against by suitable electrical heating means. Two sets of means are shown. 'Ihe first set includea a resistance element 2! of heat resisting composition extending longitudinally of the chamber and connected at its ends to the leads '2! and 22. The second heating means consists of the series or resistance rods 23 embedded in the draw bar and extending longitudinally therethrough. These rods are connected at their ends with electrical supply leads 24.

The tank construction of Figs. 3, 4 and 5 is of a dlflerent type from that 01' Figs. 1 and 2, being similar to that of the Gregorius Patent No. 2,006,- 852, dated July 2, 1935. In this construction, the o molten glass from the melting tank is conducted from a tank 280 (Fig. 5) through a pair oi conduits 2i, 2! to a draw pot or forehearth 28, which extends'transversely of the conduits. In this case, the draw bar 21 constitutes the bottom o! the forehearth, being supported by means of the wall members ll. one chambers II beneath f the draw bar are suitably heated by burners 8. which project 'throush openings at the ends or the chambers. 50

Hountedabovethedrawbanisadrawingmachinecomprisingthecaslnglandroils similar to that described in connection with the construction of Figs. 1 and 2. The glass sheet Si is drawn Irom the both above the centerotthe I6 drawbar and colored glass is supplied the center of the sheet through the slot II. which lies directlybeneath thelineofdrawofthesheetand extends the length of the draw bar. The molten colored glass is fed to the slot through the tubular delivery member 83 of refractory material which is carried at its outer end by a'day tank It,-

the bottom of the tank communicating with the delivery member through a slot in its bottom con- 33a is moved either mechanically or by hand 40 trolled by a sliding gate ii. The other end of the delivery tube is provided with a slot 38 which registers with the slot 82 in the draw bar under operating conditions. The right hand end along the lame thus withdrawing the tubular.

delivery member 33 from its position beneath the forehearth. The member 33 is guided and supported by the side walls a, a of the forehearth which have perforations therethrough in which the tube fits slidably. After the tube 33 is moved to thelef-t away from the forehearth, the slot 32 is closed by means of a follow-up plug 33a having the same outside diameter as the tube SI which is inserted through the right hand wall a as the tubular member 33 moves to the left, thus sealing the slot 3 2 at'its lower end. This structure is shown in greater detail in Figure 50, wherein the follow-up plug 330' is drilled in order that the rod ,3! controlling the plug 8'! may pass therethrough. As the"; tube 33 is withdrawn from the forehearth, the plug into position, bridgingthe space between the walls Ma and sealing-the slot 32 in the draw bar '21. 'When the is removed from operative positionafter it-has been emptied, another similar tank ,ismu'gm into position, and the operation is continued with only a short interval of time as necessitated by the substitution of tanks as above described; The heating of the chamber surrounding the tubularrmember 33 beneath the i so I 3 the glass to solidify or freeze therein.

draw 'bar serves to keep the tube and its colored glass content hot and reduces any tendency of Fig. 56 illustrates a modification, in which the gate, 42 of the day tank 34 and the plug 43 are 7 made' of heat resisting, metal. such as nickel 12.: chromium'or the like, such gate and plug being 1 operated by the rods H and 45. These rods are 'connectedto electric supply leads and 41, so

that in the operation of the device, the body of gl'asspassing through the tubular member 33 may be heated by the passage of current there- 'through, thus avoiding any danger of solidiflcar tion and serving as a means for controlling the rate of flow. The sheet produced by thi apparatus is the same as that produced by the apparatus of Figs. 1 and 2, inthat it consists of a central layer of colored glass and surface layers of' clear glass, the proportion of colored glass to clear class being regulated by the amount of colored glass fed through the draw bar.

prising a forehearth for a glass bath, means above WhatI'claimis:

1. Apparatus fo'r making a lass sheet, comprisingaforehearthfora'glas bath,meansabove v the bath'for drawing a glass sheet continuously therefrom with the lineof draw thereof trins- 5 verse to the forehearth, adra'w-bar beneath the line of draw having a vertical slot therethrough in parallel withr'said line or draw andopening downwardly through the bottom of the fore.- hearth. a tubular'delivery member beneath the forehearth having an outlet slot registering with the slot through theforehearth bottom, a contamer adapted to carry a body of molten colored lass lying at one side of the forehearth and communicating .at its'lower end with the delivery member, means'for removing the tubular delivery member and container in communication therewith from registration with respect to the vertical slot in the draw-bar, and means for clos ing the vertical slot through the draw-bar when the tubular delivery member is removed therefrom. i, formaking a glass sheet, com- 2. Apparatus prising a forehearth'for a glass bath, means above the bath for drawings. glass sheet continuously therefrom with the line of draw thereof .transverse to the forehearth, a draw-bar beneath the line of draw having a vertical slot therethrough in parallel with said line 'of draw and opening downwardly through the bottom of hearth, a container adapted to carry a body of molten colored glass locatedat one side. of the forehearth and mounted for horizontal move-- ment toward and from the, forehearth, a tubular deiivery member projecting horizontally from the with, being provided with ah'outlet slot on its upper side adapted in one position ofthe con-V tainer to registerwith the lower end of the vertical slot through the draw-bar, and means for closing the vertical slot through the draw-bar when the container and tubular delivery member are retracted from operative position. 3. Apparatus for making a glass sheet, comthe bath for drawing a glass sheet continuously therefrom with the line of draw thereof trans verse to the forehearth, a draw-bar beneath the 1: line of draw having a vertical slot therethrough downwardly through the bottom of the iorei in parallel with said line of draw and opening hearth, a containeradapted to carry-a body of molten colored glass :located at one sideoi' the forehearth and mounted for horizontal'movement toward and from the forehearth, 'a tubular delivery member projectinghorizontally from the I side of the container and communicating there,-

with, being provided with an outlet slot on its I upper side adapted in one position of the tank to register with the lower end of the vertical slot through the draw-bar, means for closing the vertical slot through the draw-bar when the tubular delivery member and container are retracted from operative position, and means exterior to the delivery tube in opposition to its outlet slot for heating the, delivery member.

JOHN 1:. FOX.

the fore-fat) g 7 v as f side of the container, andcommunicating'there 

